天然的礫石海岸具有消減波浪能量之功能，但是當其遭遇較大的波浪時，例如颱風來襲，礫石海岸依然會產生侵蝕或淤積作用。當海岸遭受侵蝕時，必須藉由海岸工程來減緩災害持續發生，例如人工養灘。本研究將藉由物理模型實驗，探討經過養灘工程後的礫石海岸受颱風尺度的不規則波作用之地形變遷。
本實驗於成功大學水工試驗所的小型斷面水槽進行，將模擬的海岸地形鋪設於1/10的斜坡上。實驗的參數有三種不同的水深、三種養灘平台長度以及兩種礫石層厚度，外加三個特殊實驗共計21種條件，並使用示性波高12公分、示性週期2.2秒的不規則波模擬颱風時期的波浪。造波結束後，使用雷射測距儀與數值高程模型測量礫石海岸的地形，並記錄越波的體積還有被沖刷的礫石重量。
實驗後藉由礫石海岸的被侵蝕比例、坡頂堆積高度與越波的消減效果作為評估依據。結果顯示幾乎所有條件的養灘地形都能達到保護海岸的效果，只是成效的高低會受到養灘平台長度與礫石層厚度的影響。另一項實驗結果發現水位的變化會使礫石往水中移動跟往陸地移動的比例產生變化。最後探討礫石量固定的情況下，提升養灘平台長度或是提升礫石層厚度，將產生不同的養灘成效。

Natural gravel beaches have the function of dissipating wave energy; however, they were still eroded or silted up especially during typhoons. When the beaches are eroded, coastal engineering must be used to mitigate disasters, such as beach nourishment. The purpose of this study is to investigate the geomorphological response of gravel beach nourishment due to irregular waves during typhoon by physical model experiment.

This experiment was carried out in a small scale wave tank at Tainan Hydraulics Laboratory, National Cheng-Kung University. To simulate the geometry of the east coast in Taiwan, a physical model was built upon a 1:10 slope. The experimental parameters included three different water depths, three lengths of berms, and two different thickness of gravel layers, besides, three special experimental conditions. Therefore, there were 21 experimental conditions in this study. Irregular waves with 12 cm significant wave height and 2.2 seconds significant wave period were used to simulate typhoon-scale wave condition. After the end of making waves, application of laser scanner and Digital Elevation Model measured the resulting morphological change of gravel beach, and then recorded the overtopping volume and the weight of gravel.

After the experiment, the erosion rate of the gravel beach, the elevation of the gravel crest and the reduction of the overtopping were used as a basis for comparison. The results showed that almost all the conditions of the beach nourishment have the effect of protecting the coast, but the level of effect would be affected by the lengths of the berms and the thickness of the gravel layer. Another result showed that the change of water level would cause the ratio of gravel offshore or overwash changed. Finally, for the cases of experiments in a fixed gravel amount, it is found that increasing the lengths of the berms or increasing the thickness of the gravel layer would result in different effects.

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